The present invention relates generally to a method and apparatus for performing liposuction, and more particularly to a method and apparatus for performing liposuction in a mechanically assisted manner using powered expedients.
Suction lipectomy, commonly known as liposuction or lipoxheresis, is a well known surgical procedure used for sculpturing or contouring the human body to increase the attractiveness of its form. In general, the procedure involves the use of a special type of curet known as a cannula, which is operably connected to a vacuum source. The cannula is inserted within a region of fatty tissue where removal thereof is desired, and the vacuum source suctions the fatty tissue through the suction aperture in the cannula and carries the aspirated fat away. Removal of fat cells by liposuction creates a desired contour that will retain its form.
Presently, there are two widely accepted techniques of liposuction and each may be practiced using a conventional liposuction cannula. The first and most common method proposed by Yves-Gerard Illouz and described in the paper xe2x80x9cIllouz""s Technique of Body Contouring by Lipolysisxe2x80x9d in Vol. 3, No. 3, July 1984 of Clinics in Plastic Surgery, involves making regular tunnels at a depth of at least 1 centimeter under the skin. According to this method, one or two insertions are made, with radial excursions of the cannula into the fatty tissue of the patient. The result is a multitude of concomitant sinuses formed below the subcutaneous fatty tissue, leaving intact as far as possible the connections between the skin and underlying tissue, thereby retaining the blood vessels, the lymphatics and the nerve endings. The second method is the original liposuction procedure proposed by U. K. Kesselring, described in xe2x80x9cBody Contouring with Suction Lipectomy,xe2x80x9d in Vol. 11, No. 3, July 1984, Clinics in Plastic Surgery. According to the technique, an entire layer of regular, deep fat is removed by aspiration through the cannula, leaving a smooth, deep surface of the residual panniculus. The space thus created is then compressed, optimally followed by skin retraction.
Both of these prior art liposuction techniques require that the surgeon push and pull the entire cannula back and forth almost twenty times for each insertion made. Typically, twenty to thirty tunnels are made. This is necessary to ensure even removal of fat in the targeted region. During this procedure, the surgeon typically massages the flesh in the area of the aperture in the cannula, while at the same time. thrusting the rod in and out of the tunnel. Due to the trauma involved during the procedure, the patient""s skin turns black and blue for several weeks. Due to the physically exacting nature of the procedure, the surgeon typically comes out of an operating room extremely tired and suffers from muscular fatigue which prevents him from performing, for some time thereafter on the delicate operations involved in ordinary plastic surgery.
Recently, the use of a xe2x80x9cguided cannulaxe2x80x9d has been proposed by R. de la Plaza, et al., described in xe2x80x9cThe Rationalization of Liposuction Toward a Safer and More Accurate Technique,xe2x80x9d published in vol. 13, Aesthetic Plastic Surgery, 1989. According to the technique, a cannula is used in conjunction with an outer guide sheath through which the cannula can slidably pass while held in place by the handle portion of the guide sheath. Once the cannula and its sheath have been introduced into the fatty tissue, the sheath guide remains in the tunnel and guides successive introductions of the cannula, keeping it in the same tunnel. While the use of this liposuction technique offers some advantages over the conventional unguided liposuction cannulas, the guided cannula nevertheless suffers from several significant shortcomings and drawbacks. In particular, the guided cannula requires manually thrusting the cannula through the guide sleeve repeatedly for each tunnel. Although this is a less physically demanding procedure, the surgeon must thrust the cannula even more times through each tunnel to achieve the desired effect and hence is still easily fatigued and prevented from performing, for some time thereafter, delicate operations involved in ordinary plastic surgery.
In an attempt to solve the above-described problem, U.S. Pat. Nos. 4,735,605 and 4,775,365 and 4,792,327 to Swartz disclose an assisted lipectomy cannula having an aspiration aperture which effectively travels along a portion of the length of the cannula, thereby obviating the necessity of the surgeon to repeatedly push the cannula in and out of the patient""s subcutaneous tissue where fatty tissue is to be removed. While this assisted lipectomy cannula can operate on either air or electric power, it nevertheless suffers from several significant shortcomings and drawbacks. In particular, the device requires an outer tube with an elongated slot and an inner tube having a spiral slot which must be rotated inside the outer tube to effectuate a traveling aspiration aperture. In addition to the device""s overall construction posing difficulties in assembly, cleaning and sterilization, use with a variety of cannulas and highly effective fat aspiration does not appear possible.
Accordingly, there is a great need in the art for a mechanically assisted lipectomy cannula which overcomes the shortcomings and drawbacks of prior art lipectomy apparatus.
Thus, it is a primary object of the present invention to provide an improved method and apparatus for performing liposuction which assists the surgeon in the removal of fat and other subcutaneous tissue (such as but not restricted to gynecomastia) from surrounding tissue, with increased control and without promoting physical fatigue.
It is another object of the present invention to provide such apparatus in the form of a hand-holdable liposuction instrument having a cannula assembly, in which the location of the aspiration aperture is periodically displaced as the inner or outer cannula undergoes sliding movement relative to the hand-holdable housing.
It is a further object to provide such a liposuction instrument in which the rate of reciprocation and the amount of excursion of the aspiration aperture, are selectively adjustable by the surgeon during the course of operation.
An even further object the present invention is to provide such a liposuction instrument which can be driven by air or electricity.
A further object of the present invention is to provide such a liposuction instrument, in which the cannula assembly can be simply detached from the hand-holdable housing for ease of replacement and/or sterilization.
An even further object of the present invention is to provide an improved method of performing liposuction, in which one of the cannulas of the cannula assembly is automatically reciprocated back and forth relative to the hand-holdable housing, to permit increased control over the area of subcutaneous tissue where fatty and other soft tissue is to be aspirated.
Another object of the present invention is to provide a power-assisted liposuction instrument, wherein means are provided along the cannula assembly to effecting hemostasis during liposuction procedures and the like.
Another object of the present invention is to provide such power-assisted liposuction instrument, wherein the hemostasis means is realized using RF-based electro-cauterization.
Another object of the present invention is to provide such a power-assisted liposuction instrument, wherein RF-based electro-cauterization is carried out by providing electro-cauterizing electrodes along the cannula assembly and supplying to these electrodes, a RF signal of sufficient power to achieve electro-coagulation and thus hemostasis during liposuction procedures.
Another object of the present invention is to provide such a power-assisted liposuction instrument, wherein the outer cannula is realized from a non-conductive material and electro-cauterizing electrode elements are inserted within the aspiration apertures thereof and electrical wiring embedded along the outer cannula and connected to a contact pad embedded within the base portion thereof, and wherein the inner cannula is made from an electrically conductive material which establishes electrical contact with contact brushes mounted within the central bore of the base portion of the inner cannula.
Another object of the present invention is to provide such a power-assisted liposuction instrument, wherein RF supply and return signals are coupled to the cannula assembly by way of the base portion of the outer cannula.
Another object of the present invention is to provide a power-assisted liposuction instrument, wherein RF-based electro-cauterization is realized using electrically conductive inner and outer cannulas which are electrically isolated by way of thin Teflon coatings applied to the outer surface of the inner cannula and/or the interior surface of the outer cannula.
Another object of the present invention is to provide a power-assisted liposuction instrument, wherein ultrasonic energy of about 40 kHz is coupled to the inner cannula in order to effect protein coagulation about the aspiration apertures and thus achieve electro-cauterization (is hemostasis) during liposuction procedures.
Another object of the present invention is to provide such a power-assisted liposuction instrument, wherein such ultrasonic energy is produced by piezoelectric crystals embedded within the base portion of the inner cannula and driven by electrical signals having a frequency of about 50 kHz.
Another object of the present invention is to provide such a liposuction instrument, wherein the electrical drive signals are supplied to the piezoelectric transducers by way of a pair of electrically conductive rails embedded within the interior surface of the cannula cavity of the hand-holdable housing of the liposuction device.
Another object of the present invention is to provide a way of carrying out RF-based cauterization within a cannula assembly, wherein the operating surgeon is enabled to perform lipolysis by driving the piezo-electric transducers within the base portion of the inner cannula with signals in the frequency range of about 20-25 kHz.
These and other objects of the present invention will become apparent hereinafter.